The fabrication of integrated circuits on a semiconductor substrate is performed by depositing a plurality of different layers, respectively having different patterns, onto a surface of the semiconductor substrate. The different patterns of the different layers are achieved through the use of photolithography, a process that uses electromagnetic radiation to transfer a geometric pattern from a photomask to a substrate.
In general, a photolithography process is initiated by depositing a layer of photoresist material onto a surface of a semiconductor substrate. The photoresist material is then selectively exposed to electromagnetic radiation (e.g., ultraviolet light), with the exposed areas defined by a photomask. After exposure, the photoresist material is subjected to a developer, which removes unwanted areas of the photoresist material to expose corresponding areas of the underlying semiconductor substrate.